Sprout for fix #248

src/main/java/com/microsoft/graph/serializer/CollectionPageSerializer.java

@@ -24,7 +24,6 @@
 
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Type;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
 
@@ -112,7 +111,7 @@ public static <T1, T2 extends BaseRequestBuilder<T1>> BaseCollectionPage<T1, T2>
             final Class<?> responseClass = Class.forName(responseClassCanonicalName);
             final JsonObject responseJson = new JsonObject();
             responseJson.add("value", json);
-            final BaseCollectionResponse<T1> response = CollectionResponseSerializer.deserialize(responseJson, responseClass, logger);
+            final BaseCollectionResponse<T1> response = CollectionResponseDeserializer.deserialize(responseJson, responseClass, logger);
             /** eg: com.microsoft.graph.requests.AttachmentCollectionRequestBuilder */
             final String responseBuilderCanonicalName = responseClassCanonicalName
                         .substring(0, responseClassCanonicalName.length() - responseLength) + "RequestBuilder";

src/main/java/com/microsoft/graph/serializer/CollectionResponseSerializer.java → src/main/java/com/microsoft/graph/serializer/CollectionResponseDeserializer.java

@@ -37,13 +37,13 @@
 import com.microsoft.graph.http.BaseCollectionResponse;
 import com.microsoft.graph.logger.ILogger;
 
-/** Specialized serializer to handle collection responses */
-public class CollectionResponseSerializer {
+/** Specialized de-serializer to handle collection responses */
+public class CollectionResponseDeserializer {
     private static DefaultSerializer serializer;
     /**
      * Not available for instantiation
      */
-    private CollectionResponseSerializer() {}
+    private CollectionResponseDeserializer() {}
     /**
      * Deserializes the JsonElement
      *
@@ -86,15 +86,7 @@ public static <T1> BaseCollectionResponse<T1> deserialize(@Nonnull final JsonEle
             for(JsonElement sourceElement : sourceArray) {
                 if(sourceElement.isJsonObject()) {
                     final JsonObject sourceObject = sourceElement.getAsJsonObject();
-                    Class<?> entityClass = serializer.getDerivedClass(sourceObject, baseEntityClass);
-                    if(entityClass == null) {
-                        if(baseEntityClass == null) {
-                            logger.logError("Could not find target class for object " + sourceObject.toString(), null);
-                            continue;
-                        } else
-                            entityClass = baseEntityClass; // it is possible the odata type is absent or we can't find the derived type (not in SDK yet)
-                    }
-                    final T1 targetObject = (T1)serializer.deserializeObject(sourceObject, entityClass);
+                    final T1 targetObject = (T1)serializer.deserializeObject(sourceObject, baseEntityClass);
                     ((IJsonBackedObject)targetObject).setRawObject(serializer, sourceObject);
                     list.add(targetObject);
                 } else if (sourceElement.isJsonPrimitive()) {

src/main/java/com/microsoft/graph/serializer/DefaultSerializer.java

@@ -22,12 +22,10 @@
 
 package com.microsoft.graph.serializer;
 
-import com.google.common.base.CaseFormat;
 import com.google.gson.Gson;
 import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
-
 import com.microsoft.graph.logger.ILogger;
 
 import java.io.IOException;
@@ -38,27 +36,28 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.Map.Entry;
-
+import java.util.Objects;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 /**
  * The default serializer implementation for the SDK
  */
 public class DefaultSerializer implements ISerializer {
-	private static final String graphResponseHeadersKey = "graphResponseHeaders";
+
+	private static final String GRAPH_RESPONSE_HEADERS_KEY = "graphResponseHeaders";
+
+    /**
+     * The logger
+     */
+    private final ILogger logger;
 
 	/**
 	 * The instance of the internal serializer
 	 */
 	private final Gson gson;
 
-	/**
-	 * The logger
-	 */
-	private final ILogger logger;
 
 	/**
 	 * Creates a DefaultSerializer
@@ -104,16 +103,7 @@ public <T> T deserializeObject(@Nonnull final JsonElement rawElement, @Nonnull f
 		if (jsonObject instanceof IJsonBackedObject) {
 			logger.logDebug("Deserializing type " + clazz.getSimpleName());
 			final JsonObject rawObject = rawElement.isJsonObject() ? rawElement.getAsJsonObject() : null;
-
-			// If there is a derived class, try to get it and deserialize to it
-			T jo = jsonObject;
-			if (rawElement.isJsonObject()) {
-				final Class<?> derivedClass = this.getDerivedClass(rawObject, clazz);
-				if (derivedClass != null)
-					jo = (T) gson.fromJson(rawElement, derivedClass);
-			}
-
-			final IJsonBackedObject jsonBackedObject = (IJsonBackedObject) jo;
+			final IJsonBackedObject jsonBackedObject = (IJsonBackedObject) jsonObject;
 
 			if(rawElement.isJsonObject()) {
 				jsonBackedObject.setRawObject(this, rawObject);
@@ -123,9 +113,9 @@ public <T> T deserializeObject(@Nonnull final JsonElement rawElement, @Nonnull f
 
 			if (responseHeaders != null) {
 				JsonElement convertedHeaders = gson.toJsonTree(responseHeaders);
-				jsonBackedObject.additionalDataManager().put(graphResponseHeadersKey, convertedHeaders);
+				jsonBackedObject.additionalDataManager().put(GRAPH_RESPONSE_HEADERS_KEY, convertedHeaders);
 			}
-			return jo;
+			return jsonObject;
 		} else {
 			logger.logDebug("Deserializing a non-IJsonBackedObject type " + clazz.getSimpleName());
 			return jsonObject;
@@ -304,52 +294,12 @@ private void addAdditionalDataFromJsonObjectToJson (final Object item, final Jso
 	 */
 	private void addAdditionalDataFromManagerToJson(AdditionalDataManager additionalDataManager, JsonObject jsonNode) {
 		for (Map.Entry<String, JsonElement> entry : additionalDataManager.entrySet()) {
-			if(!entry.getKey().equals(graphResponseHeadersKey)) {
+			if(!entry.getKey().equals(GRAPH_RESPONSE_HEADERS_KEY)) {
 				jsonNode.add(entry.getKey(), entry.getValue());
 			}
 		}
 	}
 
-	private final static String ODATA_TYPE_KEY = "@odata.type";
-	/**
-	 * Get the derived class for the given JSON object
-	 * This covers scenarios in which the service may return one of several derived types
-	 * of a base object, which it defines using the odata.type parameter
-	 *
-	 * @param jsonObject  the raw JSON object of the response
-	 * @param parentClass the parent class the derived class should inherit from
-	 * @return			the derived class if found, or null if not applicable
-	 */
-	@Nullable
-	public Class<?> getDerivedClass(@Nonnull final JsonObject jsonObject, @Nullable final Class<?> parentClass) {
-        Objects.requireNonNull(jsonObject, "parameter jsonObject cannot be null");
-		//Identify the odata.type information if provided
-		if (jsonObject.get(ODATA_TYPE_KEY) != null) {
-			/** #microsoft.graph.user or #microsoft.graph.callrecords.callrecord */
-			final String odataType = jsonObject.get(ODATA_TYPE_KEY).getAsString();
-			final int lastDotIndex = odataType.lastIndexOf(".");
-			final String derivedType = (odataType.substring(0, lastDotIndex) +
-											".models." +
-											CaseFormat.LOWER_CAMEL.to(CaseFormat.UPPER_CAMEL,
-																		odataType.substring(lastDotIndex + 1)))
-										.replace("#", "com.");
-			try {
-				Class<?> derivedClass = Class.forName(derivedType);
-				//Check that the derived class inherits from the given parent class
-				if (parentClass == null || parentClass.isAssignableFrom(derivedClass)) {
-					return derivedClass;
-				}
-				return null;
-			} catch (ClassNotFoundException e) {
-				logger.logDebug("Unable to find a corresponding class for derived type " + derivedType + ". Falling back to parent class.");
-				//If we cannot determine the derived type to cast to, return null
-				//This may happen if the API and the SDK are out of sync
-				return null;
-			}
-		}
-		//If there is no defined OData type, return null
-		return null;
-	}
 
 	/**
 	 * Gets the logger in use

src/main/java/com/microsoft/graph/serializer/DerivedClassIdentifier.java

@@ -0,0 +1,60 @@
+package com.microsoft.graph.serializer;
+
+import com.google.common.base.CaseFormat;
+import com.google.gson.JsonObject;
+import com.microsoft.graph.logger.ILogger;
+
+import java.util.Objects;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+public class DerivedClassIdentifier {
+
+    private final static String ODATA_TYPE_KEY = "@odata.type";
+
+    private final ILogger logger;
+
+    public DerivedClassIdentifier(@Nonnull ILogger logger) {
+        this.logger = Objects.requireNonNull(logger, "logger parameter cannot be null");;
+    }
+
+    /**
+     * Get the derived class for the given JSON object
+     * This covers scenarios in which the service may return one of several derived types
+     * of a base object, which it defines using the odata.type parameter
+     *
+     * @param jsonObject  the raw JSON object of the response
+     * @param parentClass the parent class the derived class should inherit from
+     * @return			the derived class if found, or null if not applicable
+     */
+    @Nullable
+    public Class<?> identify(@Nonnull final JsonObject jsonObject, @Nullable final Class<?> parentClass) {
+        Objects.requireNonNull(jsonObject, "parameter jsonObject cannot be null");
+        //Identify the odata.type information if provided
+        if (jsonObject.get(ODATA_TYPE_KEY) != null) {
+            /** #microsoft.graph.user or #microsoft.graph.callrecords.callrecord */
+            final String odataType = jsonObject.get(ODATA_TYPE_KEY).getAsString();
+            final int lastDotIndex = odataType.lastIndexOf(".");
+            final String derivedType = (odataType.substring(0, lastDotIndex) +
+                ".models." +
+                CaseFormat.LOWER_CAMEL.to(CaseFormat.UPPER_CAMEL,
+                    odataType.substring(lastDotIndex + 1)))
+                .replace("#", "com.");
+            try {
+                Class<?> derivedClass = Class.forName(derivedType);
+                //Check that the derived class inherits from the given parent class
+                if (parentClass == null || parentClass.isAssignableFrom(derivedClass)) {
+                    return derivedClass;
+                }
+                return null;
+            } catch (ClassNotFoundException e) {
+                logger.logDebug("Unable to find a corresponding class for derived type " + derivedType + ". Falling back to parent class.");
+                //If we cannot determine the derived type to cast to, return null
+                //This may happen if the API and the SDK are out of sync
+                return null;
+            }
+        }
+        //If there is no defined OData type, return null
+        return null;
+    }
+}

src/main/java/com/microsoft/graph/serializer/FallbackTypeAdapterFactory.java

@@ -22,23 +22,23 @@
 
 package com.microsoft.graph.serializer;
 
-import java.io.IOException;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Objects;
-
 import com.google.common.base.CaseFormat;
 import com.google.gson.Gson;
 import com.google.gson.TypeAdapter;
 import com.google.gson.TypeAdapterFactory;
+import com.google.gson.internal.bind.ReflectiveTypeAdapterFactory;
 import com.google.gson.reflect.TypeToken;
 import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonToken;
 import com.google.gson.stream.JsonWriter;
 import com.microsoft.graph.logger.ILogger;
 
-import javax.annotation.Nullable;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * Handles serialization/deserialization for special types (especially of
@@ -67,14 +67,14 @@ public void write(JsonWriter out, Void value) throws IOException {
         }
 
         @Override
-        public Void read(JsonReader in) throws IOException {
+        public Void read(JsonReader in) {
             return null;
         }
 
     };
 
     /**
-     * Instanciates a new type adapter factory
+     * Instantiates a new type adapter factory
      *
      * @param logger logger to use for the factory
      */
@@ -89,10 +89,21 @@ public FallbackTypeAdapterFactory(@Nonnull final ILogger logger) {
     public <T> TypeAdapter<T> create(@Nonnull final Gson gson, @Nonnull final TypeToken<T> type) {
         Objects.requireNonNull(type, "parameter type cannot be null");
         final Class<T> rawType = (Class<T>) type.getRawType();
+
         if (rawType.isEnum()) {
-            return new EnumTypeAdapter<T>(rawType, logger);
+            return new EnumTypeAdapter<>(rawType, logger);
         } else if (rawType == Void.class) {
             return (TypeAdapter<T>) voidAdapter;
+        } else if (IJsonBackedObject.class.isAssignableFrom(type.getRawType())) {
+
+            final TypeAdapter<IJsonBackedObject> delegatedAdapter = (TypeAdapter<IJsonBackedObject>) gson.getDelegateAdapter(this, type);
+
+            // Avoid overriding custom IJsonBackedObject type adapters defined in GsonFactory
+            if (!(delegatedAdapter instanceof ReflectiveTypeAdapterFactory.Adapter)) {
+                return null;
+            }
+
+            return (TypeAdapter<T>) new ODataTypeParametrizedIJsonBackedTypedAdapter(this, gson, delegatedAdapter, (TypeToken<IJsonBackedObject>) type, logger);
         }
         else {
             return null;

src/main/java/com/microsoft/graph/serializer/GsonFactory.java

@@ -239,7 +239,7 @@ public JsonElement serialize(final BaseCollectionPage<?, ?> src,
             public BaseCollectionResponse<?> deserialize(final JsonElement json,
                                         final Type typeOfT,
                                         final JsonDeserializationContext context) throws JsonParseException {
-                return CollectionResponseSerializer.deserialize(json, typeOfT, logger);
+                return CollectionResponseDeserializer.deserialize(json, typeOfT, logger);
             }
         };
 

src/main/java/com/microsoft/graph/serializer/ODataTypeParametrizedIJsonBackedTypedAdapter.java

@@ -0,0 +1,63 @@
+package com.microsoft.graph.serializer;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import com.google.gson.TypeAdapter;
+import com.google.gson.internal.Streams;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import com.microsoft.graph.logger.ILogger;
+
+import java.io.IOException;
+import java.util.Objects;
+import javax.annotation.Nonnull;
+
+/**
+ * This adapter is responsible for deserialization of IJsonBackedObjects where service
+ * returns one of several derived types of a base object, which is defined using the
+ * odata.type parameter. If odata.type parameter is not found, the Gson default
+ * (delegated) type adapter is used.
+ */
+class ODataTypeParametrizedIJsonBackedTypedAdapter extends TypeAdapter<IJsonBackedObject> {
+
+    private final FallbackTypeAdapterFactory fallbackTypeAdapterFactory;
+    private final Gson gson;
+    private final TypeAdapter<IJsonBackedObject> delegatedAdapter;
+    private final TypeToken<IJsonBackedObject> type;
+    private final DerivedClassIdentifier derivedClassIdentifier;
+
+    public ODataTypeParametrizedIJsonBackedTypedAdapter(FallbackTypeAdapterFactory fallbackTypeAdapterFactory, @Nonnull Gson gson,
+        @Nonnull TypeAdapter<IJsonBackedObject> delegatedAdapter, @Nonnull final TypeToken<IJsonBackedObject> type, @Nonnull final ILogger logger)
+    {
+        super();
+        this.fallbackTypeAdapterFactory = fallbackTypeAdapterFactory;
+        this.gson = Objects.requireNonNull(gson, "parameter gson cannot be null");
+        this.delegatedAdapter = Objects.requireNonNull(delegatedAdapter, "object delegated adapted cannot be null");
+        this.type = Objects.requireNonNull(type, "object type cannot be null");
+        this.derivedClassIdentifier = new DerivedClassIdentifier(logger);
+    }
+
+    @Override
+    public void write(JsonWriter out, IJsonBackedObject value)
+        throws IOException
+    {
+        this.delegatedAdapter.write(out, value);
+    }
+
+    @Override
+    public IJsonBackedObject read(JsonReader in) {
+        JsonElement jsonElement = Streams.parse(in);
+
+        if (jsonElement.isJsonObject()) {
+            final Class<?> derivedClass = derivedClassIdentifier.identify(jsonElement.getAsJsonObject(), type.getRawType());
+
+            if (derivedClass != null) {
+                final TypeAdapter<?> subTypeAdapter = gson.getDelegateAdapter(fallbackTypeAdapterFactory, TypeToken.get(derivedClass));
+                return (IJsonBackedObject) subTypeAdapter.fromJsonTree(jsonElement);
+            }
+        }
+
+        return delegatedAdapter.fromJsonTree(jsonElement);
+    }
+}